| 摘要 |
PURPOSE:To prevent the dielectric breakdown on the insulating film (SiO2) in an MOS thpe structure by a method wherein the third insulating film is provided on the boundary sextion where the first and the second insulating films, having a different thickness, are connected on a level, and a metallic wiring layer is formed on the upper section of the third insulating film. CONSTITUTION:For instance, an N<+> diffusion layer 3 is formed on the N type epitaxial layer 2 provided on a P type Si substrate 1 and an MOS type capacity is formed using the diffusion layer 3 and the metallic wiring layer provided through the intermediary of a thin oxide film 5. At the boundary section A where the thin oxide film 5 comes in contact with a thick field oxide film 7 on the substrate, a polymide or an Si nitride film 8, for example, are provided and it is interposed between the wiring layer 6. This insulating film is, after it has been deposited on the whole surface of the substrate through the intermediary of oxide films 5 and 6, is formed by performing a selective etching. Through these procedures, the dielectric strength at the boundary section A of the oxide film is intensified and the breakdown of the oxide film due to the static electricity and the abnormal voltage applied to the circuit from outside can be prevented. |
